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Ch. 4 - Exponential and Logarithmic Functions
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 5, Problem 101

Determine whether each equation is true or false. Where possible, show work to support your conclusion. If the statement is false, make the necessary change(s) to produce a true statement. log3 (7) = 1/[log7 (3)]

Verified step by step guidance
1
Recall the change of base formula for logarithms: \(\log_a(b) = \frac{\log_c(b)}{\log_c(a)}\) for any positive base \(c \neq 1\).
Apply the change of base formula to \(\log_7(3)\) using base 3: \(\log_7(3) = \frac{\log_3(3)}{\log_3(7)}\).
Since \(\log_3(3) = 1\), simplify the expression to \(\log_7(3) = \frac{1}{\log_3(7)}\).
Notice that this means \(\log_3(7) = \frac{1}{\log_7(3)}\), which matches the original equation given.
Therefore, the equation \(\log_3(7) = \frac{1}{\log_7(3)}\) is true, based on the properties of logarithms.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Logarithmic Functions and Notation

A logarithm log_b(a) answers the question: to what power must the base b be raised to get a? Understanding this notation is essential for interpreting and manipulating logarithmic equations.
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Change of Base Formula

The change of base formula states that log_b(a) = 1 / log_a(b). This property allows rewriting logarithms with different bases and is key to verifying or transforming logarithmic equations.
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Change of Base Property

Verifying Logarithmic Equations

To determine if a logarithmic equation is true, substitute values or apply logarithmic properties like the change of base formula. Showing work involves rewriting expressions and simplifying to confirm equality.
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